1. Field of the Invention
The present invention relates to a driving-force laterally-distributing device and, more particularly, to a technique for distributing a driving force from a driving force source such as an engine properly to left and right wheels in accordance with the running state of a vehicle.
2. Description of the Related Art
In recent years, there has been developed a device for controlling a yawing moment to act on a vehicle, by generating a driving force difference between left and right wheels at a turning time of a vehicle, thereby to improve the turning performance of the vehicle.
For example, Japanese Patent No. 2,738,225 discloses a driving-force laterally-distributing device provided with a driving force transmission control mechanism for distributing the driving forces of the left and right wheels by transmitting the driving force of an engine from an input unit, while allowing the rotation difference between the left and right wheels, through a differential mechanism to transmit the driving force to the axles of the left and right wheels and by shifting the driving force of one of the axles of the left and right wheels to the driving force of the other.
According to the technique disclosed in Japanese Patent No. 2,738,225, however, the driving force difference is established between the left and right wheels by shifting the driving force to either the left or right wheel, but cannot be limited.
Therefore, there arise a problem that the slip of the left and right drive wheels at the straight running time of the vehicle cannot be suppressed.
If the slip of the left and right drive wheels at the straight running time of the vehicle is suppressed by the technique of Japanese Patent No. 2,738,225, for example, the driving force shifts to either the left or right wheel, thereby to cause a problem that the vehicle turns.